Spray booth



J. E. LUDWIG 2,097,953

Nov. 2, 1937.

SPRAY BOOTH Filed March 28, 1935 IINVEQNTOR, l /o/fz @[z ATTORNEY.

Patented Nov. 2, 1937 I UNITED STATES PATENT OFFICE SPRAY BOOTH John E. Ludwig, Detroit, Mich., assignor to Newcomb David Company, Inc., Detroit, Mich., a corporation of Michigan Application March 28, 1935, Serial No. 13,463 4 Claims. (01. 9160) This invention relates to spraying booths for laden air first passed through a washer where installation in buildings where automobile bodies, it was merely dampened by a light spray of water furniture or other articles are to be sprayed with and the majority of the particles and synthetic paint, or the like. enamel or other material carried by the air was Spray booths per se are not new. Nor is it deposited on the eliminator plates, from which 5 broadly new to provide some form of air cleaning they are not easily recovered without damaging or conditioning means in spray booths. Various them. Hence but small amounts of such parmeans for cleaning or conditioning air have long ticles of enamel or paint were recoverable from been known in other arts, and heretofore various the prior types of spray booths.

adaptations thereof have been applied to the The recovered particles of synthetic enamel 0 spray booth art. or paint are sent to the refiner where they are It has long been known that water sprayed into easily reclaimed. At the present market value a stream of air impregnated with dust or dirt of such recovered particles of synthetic enamel or caused most of the particles of dust or dirt to bepaint, it is possible by the use of my invention to come saturated or heavy and therefore to fall, 'makeasubstantial saving on the operation of the 15 while the remainder of the air is humidified to a spraying department of a plant. considerable degree,--the air being washed, so to It is therefore an object of this invention to speak. provide means for efiiciently separating from the In spray booths the problem in the past was fume-laden air the synthetic enamel or other not primarily one of removing dust from the air, paint substances which might otherwise be wasted 20 but, on the contrary, it was one of quickly removin the spraying operation. To this end, I proing poisonous and easily combustible fumes from vide means for directing the fume-laden air the vicinity of the workmen and preventing them downwardly and directly into a water chamber from coming in contact with any means of igand thence toward the opening of an air washing niting the same. There is also aproblem of overmeans wherein I deluge it with water in tubes 25 coming a great amount of waste which now preover a tank, permitting the particles of synthetic vails on account of loss of particles of the subenamel or paint to fall into the tank wherein stance used for spraying and by reason of the cost they settle on the botom and from which they of constant cleansing and enforced idleness of are easily recovered, as for instance by means of the booth during the cleaning operations. shoveling. 30

For a long time it has been customary to use It is also of considerable economic value to be synthetic enamel and other expensive paint subable to recirculate the water used for washing the stances for spraying articles by the use of an air air in a spray booth and therefore it has become brush operating under a high pressure of apa common practice to do so. However, in former proximately 80 lbs. per square inch. Particles of devices, a plurality of small spraying nozzles 35 the synthetic enamel or paint are therefore, blown have been used, sending a fine spray into the air, on the floor or on parts of the booth and thus which as previously stated, merely dampened air are wasted unless they are properly directed into and did not remove all the particles of synthetic the air washing means and unless they are sepaenamel or paint therefrom. Thus, as the recircu- 40 rated from the paint-laden air. lated water became saturated with such particles, 40

In some instances, prior devices have been the said nozzles would become clogged. As more provided with bafile plates against which the of them became clogged, more and more of the paint-laden air is first directed, (supposedly to delivery water would cease and finally all would cause all the particles of synthetic enamel or cease and thepaint-laden air would then carry paint to be impinged thereagainst, causing said directly to the eliminator plates and thus would 45 particles to drop into a drip tank) after which the soon cause a clogging of the whole apparatus. air passes through a thin water spray which Such clogging not only necessitates and incurs serves to absorb and carry off much of the deadly expense for having the parts cleaned out, but and inflammable fumes. However, many of the causes a loss of production in the interim.

particles stick to the baffle plates and are not Hence it is another object of this invention to 50 easily recovered. Moreover, the sprays have not provide a spray .booth that does not easily get been of the right type to suificiently separate all dirty or clogge' and therefore become a great the particles of synthetic enamel or paint from economic asset to a factory engaged in quantity the air. production of parts to be painted.

In some types of prior devices, the fume- Other-objects of my invention reside in the 55 provision of a spray booth that does not interfere with the rapid passage of conveyors therethrough carrying the objects to be sprayed; that quickly drains off the air impregnated with deadly and dangerous fumes or other impurities; that quick- 1y washes and humidifies the same so that it may be again used in the factory or building when desired to conserve heat; that is simple in construction and is economical both to manufacture and to operate.

These and other objects and novel features of the invention will more fully appear from the description and the accompanying drawing in which,

Fig. 1 is a view in elevation and partly in section showing the preferred embodiment of my invention, the air washing unit being on one side of the spraying compartment and provided with a passage under the compartment for causing a down draft to the air in the spraying compartment;

Fig. 2 is a view in end elevation, the pipes and pump being'removed;

Referring to the drawing, the floor of a building is indicated at I. In the embodiment of my invention illustrated in Figures 1 and 2, the spray room, hereinafter designated A, is provided with an independent floor'2, raised from the floor I and supported by other portions of the air cleaning unit hereinafter to be described.

In the illustration shown in Figs. 1 and 2, I place a water tank 3 upon the floor I and upon this tank the floor 2 is supported. At one end of the tank 3 I provide an enlarged air chamber 4 opening into the tank 3, and above the same and communicating therewith I mount two large hollow cylinders 5, preferably of circular bore, said cylinders opening into an eliminator chamber generally designated by the numeral 6.

The water eliminator 6 is formed with a plurality of vertically extending plates 1 so shaped as to change the direction of the flow of air many times as it passes therethrough.

The top of the eliminator is connected for communication with a pneumatic conveyor system comprising pipe or conduit 8 and exhaust fan 9 with the usual motor and exhaust outlet.

The spray booth is provided with the room A where the actual spraying is done, said room comprising side members It and I 2, the latter being preferably curved to rest upon a portion of the floor 2 as shown in Fig. 1 and said sides support a roof I3. The other two sides of the booth are open to accommodate a conveyor passing therethrough with the object to be sprayed, or they may have a partial enclosure for that portion where the workman stands, such as the portion designated as 36.

In the preferred embodiment shown in Fig. 1 the roof I3 is provided with a circular grilled passage l4 and a suitable intake I5 is connected to said roof and adapted to guide air to the said grilled portion M.

The roof portion I3 is preferably slanted near each side towards the side members II and 12 as shown at IS, in order to accommodate the usual lights used in such work.

The floor 2 is provided with a plurality of openings or a grilled portion 20 toward the side remote from the air chamber 4 and with a single opening 2| near the side adjacent to said air chamber 4*.

A water pipe 22 is connected to the tank 3 and to a water pump 23 which forces water up through a. pipe 24 thence through branch pipes 25, each branch pipe passing into a cylinder 5 and each branch pipe terminates in a double op- I ducting air through said roof, a water reservoir under said floor, venting apertures in said floor spaced from the first one of said side walls for venting the spray room into said water reservoir, additional venting means in said floor adjacent the second one of the side walls, air circulating means, a conduit conductively connecting said air circulating means for drawing air from said water reservoir, and a double nozzlein said conduit for discharging a heavy spray of water across the entire cross-section of the conduit whereby all the air drawn from the water reservoir under the spray room must pass through said water spray.

2. A ventilated paint reclaiming spray booth having in combination a spray room including a roof, side walls, and floor, a water reservoir under said floor. venting apertures in said floor for venting the spray room into said water reservoir, air circulating means, a conduit conductively connecting said air circulating means for drawing .air from said water reservoir whereby the paint spray is carried downwardly from the spray booth into the water reservoir, a double nozzle in said conduit for discharging a heavy spray of water across the entire cross-section of the conduit whereby all the air drawn from the water reservoir under the spray room must pass through said water spray, and means for supplying water to said double nozzle from said water reservoir whereby the water is reclaimed for depositing reclaimed material in said reser- V011.

3. A ventilated paint reclaiming spray booth having in combination a roof, side walls and a floor enclosing a spray room, an air inlet for conducting air into the upper portion of said spray room, a water reservoir under said floor,

venting apertures in the floor for venting the spray room into said water reservoir, air circulating means, a conduit connecting said air circulating means for drawing the air from said water reservoir, and a water spray nozzle in said conduit for discharging a heavy spray of water across said conduit whereby all the air which is drawn from the spray room down into the water reservoir under the spray room is thoroughly washed thereby as it is drawn through said conduit and thepaint particles are collected in said reservoir.

4. In combination with a spraying booth, an enclosed chamber connected to said booth by a passage, said chamber presenting a liquid surface opposed. to a jet passing from said booth through said passage and means for maintaining a vacuum in said chamber, and means for washing the air withdrawn from said chamber and returning the washed-out matter to said cham-' ber.

JOHN E. LUDWIG. 

